Concrete container for vacuum applications

ABSTRACT

The invention relates to a container for vacuum applications comprising a concrete casing, the casing of the container being provided internally or externally with a coating having a tensile adhesive strength which at least corresponds to an external pressure loading of one bar. The concrete is preferably in the form of reinforced concrete, and the coating is a polymer, preferably an epoxy resin.

This is a regular national application filed under 35 U.S.C. §111(a) and 37 CFR §1.53(b), more particularly, a continuation of International Application PCT/DE2007/000228 with an international filing date of Feb. 7, 2007, published as WO 2007/095888 A2 on Aug. 30, 2007, said International Application claiming priority to German national application DE 10 2006 008285.0 filed on Feb. 22, 2006, each of which are incorporated herein in their entireties. The subject application claims priority to each of said prior applications.

TECHNICAL FIELD

The invention relates to a container out of concrete for vacuum applications.

BACKGROUND OF THE INVENTION

From the state of the art, containers out of concrete are well known for carrying out, therein, dangerous experiments and processes without endangering the environment. For example, balancing and rotating of rotors for high speed machines requires particular security measures since various dangerous hazards originate from the very fast rotating rotors which have to pass through critical rotational speed ranges during the acceleration to their maximum rotational speed. For example, balancing weights or parts of the rotor may become loose which are, thereafter, hurled off with high energy. In extreme cases, breakage of the rotor may be encountered. In order to prevent serious damage by such high energy projectiles, larger rotors are balanced in housings out of steel reinforced concrete.

Whereas rotors without blades are balanced and rotated under atmospheric conditions, the air resistance associated with bladed rotors, for example turbines, would lead to an inadmissible heating of the rotor and would require extremely high driving power. Therefore, bladed rotors are balanced and rotated under vacuum conditions. The housings required therefore, are built, up to now, in such a way that a vacuum tight steel envelope is constructed at first around the rotor with a steel envelope withstanding the load of the outside pressure. The steel envelope is, thereafter, covered by casting steel reinforced concrete around it in order to protect the environment against structural parts which are probably hurled off from the rotor.

SUMMARY OF THE INVENTION

An advantageous embodiment of the invention is characterized in that the container out of concrete is arranged in such a way to balance rotors in its interior under vacuum conditions. Therefore, rotors may be balanced economically and safely under vacuum conditions.

With such containers, it is advantageous that the parts of a rotor or balancing weights which come off from the rotor at high rotational speeds and which are hurled off with high energy, can safely be intercepted. Thereby, rotors may be economically balanced under vacuum conditions without endangering the environment by parts which may be hurled off with high energy from the rotor in case of possible damages.

A further advantageous embodiment of the invention is characterized in that the rotors to be balanced are turbines or compressors which are provided with blades. Therein, the rotors may be constructed such that the blades are attached themselves to the rotor or such that the rotors carry bladed impellers. Thereby, turbines or compressors may be economically and safely balanced without larger ventilation losses leading to an unacceptable heating of the rotor and without the need for extremely high driving power.

A further advantageous embodiment of the invention is characterized in that the rotors to be balanced are constructed to be used in motors or generators and comprise electric coils. Thereby, rotors designed for the use in motors or generators, may be balanced in a particular economic way in vacuum containers without parts of the coils which become disintegrated from the rotor at high rotational speeds, endangering the environment.

It is an object of the invention to economically further develop such a container out of concrete in such a way that also processes and experiments can be carried out therein which have to be carried out under vacuum conditions. This object is achieved in that a container out of concrete is provided inside or outside with a coating which exhibits an adhesive tensile strength which corresponds at least to an external pressure load of 1 bar. Such a container may be manufactured economically and can be handled easily since no additional vacuum envelope, for example out of steel, has to be installed inside or outside of such a container out of concrete. Moreover, such a container uses the available space particularly efficiently since no additional space for an additional vacuum envelope is needed neither inside nor outside of the container.

In an advantageous embodiment of the invention, the container is formed out of steel reinforced concrete. This enables a stable but never the less economic and time-saving production in particular with larger containers.

A further advantageous embodiment of the invention is characterized in that the coating comprises a suitable plastics material, in particular a suitable epoxy resin. Plastic materials or epoxy resins, respectively, having the required air tightness and adhesion tensile strength, are low priced and may be formed into a coating of a container having an arbitrary shape, particularly simple prior to curing. In a particular embodiment, the epoxy resin is a two-component epoxy resin.

In a further advantageous embodiment, the container comprises suction stubs and hatches whereby the container can be evacuated particularly easily and the installations necessary for carrying out the processes under vacuum, may be placed particularly easily into the interior of the container.

A further advantageous embodiment of the invention is characterized in that the suction stubs and hatches are cast into the concrete by means of suitable flange adapters. Thereby, the suction stubs and hatches may be opened, closed, maintained and, if necessary, exchanged in a particularly simple way without damaging the concrete or the vacuum-tight coating.

A further advantageous embodiment of the invention is characterized in that the container is configured to be hermetically sealed and to be evacuated by means of a vacuum pump installation to a desired end pressure. Because of this advantageous arrangement, experiments and processes under vacuum conditions may be carried out in a simple and economic way in the container of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a sectional view of a preferred embodiment of the concrete container of the subject invention.

DETAILED DESCRIPTION OF THE INVENTION

The invention becomes clearer by the following detailed description of an embodiment where FIG. 1 shows a sectional view through a container 1 according to the invention. A rotation axis 7 extends horizontally in the middle of the figure from left to right. The embodiment of the container 1 of the invention shown in FIG. 1 is rotationally symmetric about the rotation axis 7.

At the far left, FIG. 1 shows a hatch 5 which is connected to a steel flange 4. The hatch comprises a circular groove 5 a, into which a sealing ring 11 is inserted. Such sealing rings 11 are known to persons of ordinary skill in the art and are made, for example, out of rubber or cacutchouc. This sealing ring 11 hermetically seals the connection between the hatch 5 and the steel flange 4.

The steel flange 4 is followed by a glue layer 10 to the right hand side which is followed by the concrete envelope 2. The glue layer connects the steel flange 4 air-tightly to the concrete envelope 2. In another alternative embodiment, not shown, the steel flange 4 is air-tightly cast into the concrete envelope without the use of a glue layer 10.

The concrete envelope 2 comprises a rotationally symmetric interior space 8 around the rotation axis 7. The concrete envelope 2 is completely covered with a coating 3 on its side facing the interior space 8. The coating 3 exhibits an adhesive tensile strength which corresponds at least to an outer pressure load of 1 bar. In an alternative embodiment not shown, the coating 3 is applied to the outer walls 9 a, 9 b of the concrete envelope.

In a particularly advantageous embodiment, the coating 3 consists of a suitable plastics material, more particularly, a suitable epoxy resin. Such plastic materials are economic, very durable and can be adapted into different shapes of the interior space and processed in a particular easy way.

At the end of the concrete envelope 2 shown to the right hand side in FIG. 1, a steel flange 6 is air-tightly cast into the concrete envelope 2. Through this steel flange, for example a vacuum pump not shown in FIG. 1, may be connected in order to evacuate the interior space 8 of the container. In an alternative embodiment, not shown, the steel flange 6 is fixed air-tightly to the concrete envelope 2 by means of a glue layer 10.

The experimental and processing installations required for carrying out the experiments and processes under vacuum conditions are inserted through the hatch 5 into the container 1 and are, later on, again removed therefrom.

In a particular advantageous embodiment, the balancing apparatus for balancing of rotors is placed into the container. Rotors for balancing may include but are not limited to turbines or compressors, with blades or motors or generators having electric coils.

It is to be understood that this disclosure, in many respects, is only illustrative. The preferred forms of the invention described above are to be used as illustration only, and should not be utilized in a limiting sense in interpreting the scope of the present invention. Obvious modifications to the exemplary embodiments, as hereinabove set forth, could be readily made by those skilled in the art without departing from the spirit of the present invention and scope of the appended claims. Changes may be made in a variety of details, particularly in matters of shape, size, material, and arrangement of parts, as the case may be, without exceeding the scope of the invention. 

1-15. (canceled)
 16. A container for vacuum applications comprising a concrete casing, said concrete casing including an a coating upon an interior or exterior surface thereof, said coating having having an adhesive tensile strength which at least corresponds to a pressure load of 1 bar.
 17. The container according to claim 16, wherein said concrete casing is formed of steel reinforced concrete.
 18. The container according to claim 16, wherein said coating comprises a plastic material.
 19. The container according to claim 18, wherein said plastic material comprises an epoxy resin.
 20. The container according to claim 19, wherein said epoxy resin is a two-component epoxy resin.
 21. The container according to claim 16, wherein said concrete casing includes a suction stub and hatches.
 22. The container according to claim 21, wherein said suction stub and said hatches are fixed to flange adapters which are cast into said concrete casing.
 23. The container according to claim 21, wherein said suction stub and said hatches are fixed to flange adapters which are fixed to said concrete casing by means of a glue layer.
 24. The container according to claim 16, wherein said concrete casing is configured to be hermetically sealed and to be evacuated by a vacuum pump to a preselect final pressure.
 25. The container according to claim 16, wherein said concrete casing is dimensioned to balance rotors under vacuum conditions in an interior compartment thereof.
 26. The container according to claim 25, wherein the rotors comprise turbines or compressors.
 27. The container according to claim 25, wherein the rotors include plates.
 28. The container according to claim 27, wherein the plates are fixed to the rotor.
 29. The container according to claim 25, wherein the rotors carry plated impellers.
 30. The container according to claim 25, wherein the rotors are configured for use in electro motors or generators and comprise coils. 